Efimov physics is famous for its self-similar energy spectrum, where strongly interacting few particles form an infinite series of cluster states that obey the discrete scale invariance. Because of the self similarity, universality of the Efimov physics is characterized by the renormalization-group limit cycle where the renormalization-group flow forms a periodic circle rather than converges to a fixed point. In this seminar, we present a close connection between the universal properties of the Efimov physics and geometrical properties of the limit cycle. In particular, the one-to-two correspondence of the numbers of trimers and tetramers would be identified with topological numbers in terms of the limit cycle.

連絡教員　物理学系　西田 祐介（内線3614）